Hair-spring stud.



W. 0. BALL 6/: L. N. COBB.

HAIR-SPRING STUD.

APPLICATION FILED APR. 9. 1908.

906,366 Y Patented Dec. 8, 1908.

1n: NORRIS PETERS ca., WASHINGTON, n. c.

UNITED STATES PATENT OFFICE.

WEBSTER 0. BALL AND LAVERNE N. COBB, OF CLEVELAND, OHIO.

HAIR-SPRING STUD.

Application filed. April 9, 1908. Serial No. 425,977.

To all whom it may concern.

Be it known that we, WnBsTnn 0. BALL and LAVERNE N. COBB, citizens of the United States, residents of Cleveland, county of Cuyahoga, State of Ohio, have jointly invented a new and useful Improvement in Hair-Spring tuds, of which the following is a specification, the principle of the invention being herein explained and the best mode in which we have contemplated applying that principle, so as to distinguish it from other inventions.

The present invention relates to the mode of attachment of the outer ends of hair springs or balance springs in watches, chronometers and the like.

Said invention relates more particularly to such attachment in the case of over-coil or Breguet springs, which consist of a volute having its outer end bent up above the plane of the body of the spring and carried in a long curve towards the center near which it is fixed. It is not intended, however, to necessarily limit the application of our improved construction for securing such outer spring ends to this particular type of spring alone.

The object of the invention is to provide a more simple and efficient mode of attachment for such outer spring ends than are found in prevailing constructions and one in particular that will permit of the securing of the spring, after being unpinned, again in the same position as that which it occupied before, this being essential to prevent derangement of the adjustment of the time-piece.

To the accomplishment of the above and related objects said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawing and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawing: Figure 1 represents in plan view the balance cock of a watch together with appurtenant parts including the balance spring; Fig. 2 represents the same with certain parts in a different position and with the balance wheel omitted; Fig. 3 represents in perspective the outer end of a balance spring such as is employed in connection with the mounting illustrated in Figs. 1 and 2 and Figs. 4 and 5 views similar Specification of Letters Patent.

Patented. Dec. 8, 1908.

to Figs. 1 and 2 but showing a slightly modified construction.

it is generally recognized that the stud for the attachment of the outer end of the balance spring has been a weak point in watch and chronoineter construction. In the older forms of watches the spring has to be unpinned every time the balance is removed and as a consequence is often distorted or broken at its point of attachment. The more modern method of fastening the stud to the balance cock by means of a screw, whether applied directly to hold the stud in place or to clamp a cover plate upon the head of the latter as in most Swiss movements, is likewise open to objection since it is difficult to always secure an exact return of the parts to their former position and by drawing the screw, or screws in the case of the cover plate, more tightly or less tightly sufficient distortion of the spring to affect the regularity of-its action may easily be produced, which is a serious difiiculty where accuracy in running is sought.

The incorporation of our improved means of attachment in the watch movement does not involve any reconstruction or new arrangement of the latter as will be obvious from reference to the several figures of the drawing, wherein A will be seen to designate the bottom plate of a watch upon which is mounted a balance cock A of the usual construction. In the outer end of the latter is mounted in suitable bearings the balance wheel a, the particular construction of which is immaterial so far as the present invention is concerned. Suitably mounted in conjunction with such balance wheel, or balance as it may be more simply styled, is the balance spring or hair spring B by which vibration of the wheel is governed. The inner end of such spring is of course attached to the staff of the balance, such attachment being had in any approved fashion, it being to the mode of attachment of its outer end alone that attention is here directed. Such spring being, as before indicated, of the Breguet or over-coil type, this outer end I) is bent up above the plane of the body of the spring to a point adjacent to one lateral surface or edge of the balance cock. Outer end I) is of course loosely held, at a point intermediate of the body of the spring and this point of attachment of its end, between curb pins a supported in the usual fashion from a projecting arm a adjustably mounted upon the terminal portion of the balance cook.

The outer spring end bears as a means for afliXing it in the manner just described a stud of the form of which as well as the mode of attachment of the spring end thereto is clearly shown in Fig. 3; the head of this stud, however, it should be stated, need not necessarily be of the triangular form there illustrated, although this is preferred. To secure such stud and head of the spring against movement, an elongated resilient member in the form of a flat spring a lying laterally of the balance cock A is secured at its rear end thereto by a screw a, the outer end of said member normally bending away as shown in Fig. 2. This outer end is formed on its inner face with an annular recess a corresponding in form with that of the head of the stud b so that when said member is pressed against the lateral face, to which it is attached, this stud will likewise be pressed solidly thereagainst and held against rotation or other movement in a definitely fixed position. The outer end of resilient member a is thus drawn or pressed against the side of the bal ance cock by means of a screw a passing therethrough and into the lateral face of the latter.

It will accordingly be seen that by simply loosening this screw the hair spring stud and spring are left free for the purpose of removal or such other attention as the spring may re quire. When it becomes necessary again to attach the spring end in place it is a very simple operation to engage the angular head of the stud in the recess provided for its reception in the end of resilient member a and, by drawing the latter by means of screw a up against the side of the balance cock, to secure all parts in their proper positions. Not only does our construction present the ad vantage that if removed the stud may be replaced with certainty in unaltered relation to the spring, but all possibility of imposing even a slight strain transversely of the spring or otherwise distorting the same is eliminated as Well.

The modification illustrated in Figs. 4 and 5 consists simply in forming the recess, 0r notch, here designated by letter a, in the lateral edge of the balance-cock instead of in the end of spring (L The latter, when closed down by screw a serves to secure the hair-spring stud 5 against movement just as effectively as in the other arrangement of parts.

Other modes of applying the rinciple of our invention may e employe instead of the one explained, change being made as regards the mechanism herein disclosed, rovided the means stated by any of the fol owing claims or the equivalent of such stated means be employed.

We therefore particularly point out and distinctly claim as our invention 1. The combination with the hair-spring and balance cock of a watch, of a stud borne by the outer end of said spring, a resilient member lying laterally of said balance cock and attached at one end thereto, the other end of said member normally bending away from said balance cock and being adapted to engage and press said stud against the same, and means adapted to draw such free end of said member against said balance cock.

2. The combination with the hair-spring and balance cock of a watch, of an angular stud borne by the outer end of said spring, a resilient member lying laterally of said balance cock and attached at one end thereto, the other end of said member normally bending away from said balance cock and the contiguous faces of such end and balance cock being formed to receive said angular stud, and means adapted to draw such free end of said member against said balance cock, whereby said stud is secured to the latter.

3. The combination with the hair-spring and balance cock of a watch, of a triangular stud borne by the outer end of said spring, a resilient member lying laterally of said balance cock and attached at one end thereto, the other end of said member normally bending away from said balance cock and being formed with an angular recess on its inner face adapted to receive said stud, and a screw adapted to draw such free end of said member, and thereby secure said stud, against said balance cock.

Signed by us this 18th day of March, 1908.

WEBSTER 0. BALL. LAVERNE N. COBB. Attested by:

E. R. Rom), JNo. F. OBERLIN. 

